<?php
/**
* jsmin.php - PHP implementation of Douglas Crockford's JSMin.
*
* This is pretty much a direct port of jsmin.c to PHP with just a few
* PHP-specific performance tweaks. Also, whereas jsmin.c reads from stdin and
* outputs to stdout, this library accepts a string as input and returns another
* string as output.
*
* PHP 5 or higher is required.
*
* Permission is hereby granted to use this version of the library under the
* same terms as jsmin.c, which has the following license:
*
* --
* Copyright (c) 2002 Douglas Crockford (www.crockford.com)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do
* so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* The Software shall be used for Good, not Evil.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
* --
*
* @package JSMin
* @author Ryan Grove <ryan@wonko.com>
* @copyright 2002 Douglas Crockford <douglas@crockford.com> (jsmin.c)
* @copyright 2008 Ryan Grove <ryan@wonko.com> (PHP port)
* @license http://opensource.org/licenses/mit-license.php MIT License
* @version 1.1.1 (2008-03-02)
* @link http://code.google.com/p/jsmin-php/
*/

class JSMin {
	const ORD_LF = 10;
	const ORD_SPACE = 32;

	protected $a = '';
	protected $b = '';
	protected $input = '';
	protected $inputIndex = 0;
	protected $inputLength = 0;
	protected $lookAhead = null;
	protected $output = '';

	// -- Public Static Methods --------------------------------------------------

	public static function minify($js) {
		$jsmin = new JSMin($js);
		return $jsmin->min();
	}

	// -- Public Instance Methods ------------------------------------------------

	public function __construct($input) {
		$this->input = str_replace("\r\n", "\n", $input);
		$this->inputLength = strlen($this->input);
	}

	// -- Protected Instance Methods ---------------------------------------------

	protected function action($d) {
		switch($d) {
			case 1:
				$this->output .= $this->a;

			case 2:
				$this->a = $this->b;

				if ($this->a === "'" || $this->a === '"') {
					for (;;) {
						$this->output .= $this->a;
						$this->a = $this->get();

						if ($this->a === $this->b) {
							break;
						}

						if (ord($this->a) <= self::ORD_LF) {
							throw new JSMinException('Unterminated string literal.');
						}

						if ($this->a === '\\') {
							$this->output .= $this->a;
							$this->a = $this->get();
						}
					}
				}

			case 3:
				$this->b = $this->next();

				if ($this->b === '/' && (
						$this->a === '(' || $this->a === ',' || $this->a === '=' ||
						$this->a === ':' || $this->a === '[' || $this->a === '!' ||
						$this->a === '&' || $this->a === '|' || $this->a === '?')) {

					$this->output .= $this->a . $this->b;

					for (;;) {
						$this->a = $this->get();

						if ($this->a === '/') {
							break;
						} elseif ($this->a === '\\') {
							$this->output .= $this->a;
							$this->a = $this->get();
						} elseif (ord($this->a) <= self::ORD_LF) {
							throw new JSMinException('Unterminated regular expression '.
									'literal.');
						}

						$this->output .= $this->a;
					}

					$this->b = $this->next();
				}
		}
	}

	protected function get() {
		$c = $this->lookAhead;
		$this->lookAhead = null;

		if ($c === null) {
			if ($this->inputIndex < $this->inputLength) {
				$c = substr($this->input, $this->inputIndex, 1);
				$this->inputIndex += 1;
			} else {
				$c = null;
			}
		}

		if ($c === "\r") {
			return "\n";
		}

		if ($c === null || $c === "\n" || ord($c) >= self::ORD_SPACE) {
			return $c;
		}

		return ' ';
	}

	protected function isAlphaNum($c) {
		return ord($c) > 126 || $c === '\\' || preg_match('/^[\w\$]$/', $c) === 1;
	}

	protected function min() {
		$this->a = "\n";
		$this->action(3);

		while ($this->a !== null) {
			switch ($this->a) {
				case ' ':
					if ($this->isAlphaNum($this->b)) {
						$this->action(1);
					} else {
						$this->action(2);
					}
					break;

				case "\n":
					switch ($this->b) {
						case '{':
						case '[':
						case '(':
						case '+':
						case '-':
							$this->action(1);
							break;

						case ' ':
							$this->action(3);
							break;

						default:
							if ($this->isAlphaNum($this->b)) {
								$this->action(1);
							}
							else {
								$this->action(2);
							}
					}
					break;

				default:
					switch ($this->b) {
						case ' ':
							if ($this->isAlphaNum($this->a)) {
								$this->action(1);
								break;
							}

							$this->action(3);
							break;

						case "\n":
							switch ($this->a) {
								case '}':
								case ']':
								case ')':
								case '+':
								case '-':
								case '"':
								case "'":
									$this->action(1);
									break;

								default:
									if ($this->isAlphaNum($this->a)) {
										$this->action(1);
									}
									else {
										$this->action(3);
									}
							}
							break;

						default:
							$this->action(1);
							break;
					}
			}
		}

		return $this->output;
	}

	protected function next() {
		$c = $this->get();

		if ($c === '/') {
			switch($this->peek()) {
				case '/':
					for (;;) {
						$c = $this->get();

						if (ord($c) <= self::ORD_LF) {
							return $c;
						}
					}

				case '*':
					$this->get();

					for (;;) {
						switch($this->get()) {
							case '*':
								if ($this->peek() === '/') {
									$this->get();
									return ' ';
								}
								break;

							case null:
								throw new JSMinException('Unterminated comment.');
						}
					}

				default:
					return $c;
			}
		}

		return $c;
	}

	protected function peek() {
		$this->lookAhead = $this->get();
		return $this->lookAhead;
	}
}

// -- Exceptions ---------------------------------------------------------------
class JSMinException extends Exception {}
?>